• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.387-389
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• 2001

• Journal of Mechanical Science and Technology
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• v.15 no.10
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• pp.1380-1385
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• 2001

This paper evaluates the fatigue fracture behavior of a chopped strand glass mat/polyester composite both in ai, and sea water, Bending fatigue (R=-1) was performed on dry and wet specimens, that is respectively in air and sea water. Where the pH concentration of sea water was controlled to 6.0,8.2, 10.0 and the wet specimens were immersed in the sea waters for 4 months. Throughout the tests, fatigue cracks both in the dry and wet specimens, tested in the air or sea water, occurred at the beginning of the cycle, followed by either of two regions one decreasing and the other increasing as the crack growth rate increases.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.17-23
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• 2009

The gene encoding Thermus thermophilus HJ6 DNA polymerase (Tod) was cloned and sequenced. The open reading frame (ORF) of the Tod gene was composed of 2,505 nucleotides and encoded a protein (843 amino acids) with a predicted molecular weight of 93,795 Da. The deduced amino acid sequence of Tod showed 98% and 86% identities to the Thermus thermophilus HB8 DNA pol and Thermus aquaticus DNA pol, respectively, The Tod gene was expressed under the control of the bacteriophage $\lambda$ promoters PR and PL on the expression vector pJLA503 in Escherichia coli strain BL21 (DE3) codon plus. The expressed enzyme was purified by heat treatment, $HiTrap^{TM}$ Q column, and $HiPrep^{TM}$ Sephacryl S-200 HR 26/60 column chromatographies. The optimal temperature and pH for DNA polymerase activity were found to be $75{\sim}80^{\circ}C$ and 9.0, respectively. The optimal concentrations of $Mg^{2+}$ and $Mn^{2+}$ were 2.5 mM and 1 mM, respectively. The enzyme activity was activated by divalent cations, and was inhibited by monovalent cations. The result of the PCR experiment with Tod DNA polymerase indicates that this enzyme might be useful in DNA amplification and PCR-based applications.

• Economic and Environmental Geology
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• v.42 no.2
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• pp.107-120
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• 2009

Spacial variation in organic components and temporal variation in the origin was examined through the organic geochemical (TC, TN, TS, $CaCO_3$, TOC, C/N, and $\delta^{13}C$) and pyrolysis analysis (HI, OI, and Tmax) in the core sediments which were acquired in the continental shelf of the South Sea close to Seomjin River. Levels of TC, TN, and TS show relatively low and constant in the core SJ03 located close to the Seomjin River mouth, while those are increased a little with being varied with low amplitude in the core SJ02 and SJ04 acquired at the middle of inner shelf area. They fluctuated with high amplitude in the core SJ01 and SJ05 near to the outer boundary of inner shelf. The vertical characteristics of organic components in the core SJ01 acquired at the outer boundary show that the area has undergone distinctly the environmental change at 9.0 kyr B.P. After 9.0 kyr B.P., Levels of TC, TOC, TN, $CaCO_3$, $\delta^{13}C$, HI, and Tmax are rapidly increased, while C/N and or are significantly decreased. Even though the contents of organic components are not high, such a changes reflect that the terrigenous organic matters were predominant before 9.0 kyr B.P due to the influence of Seomjin River, but after then, the marine organic matters have dominated due to the inflow of the Tshusima current.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1C
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• pp.45-51
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• 2010

In urban area, design and construction of civil engineering structures such as subway tunnel, underground space and deep excavation is impeded by unreliable site investigation. Variety of embedded objects, electric noises and traffic vibrations degrades the quality of site investigation, whatever the site-investigation technique would be. In this research, a preliminary research was performed to develop a dedicated site investigation technique for urban geotechnical sites, which can overcome the limitations of urban sites. HiRAS (Hybrid Integration of Surface Waves and Resistivity) technique which is the first outcome of the preliminary research was proposed in this paper. The technique combines surface wave as well as electrical resistivity. CapSASW method for surface-wave technique and PDC-R technique for electrical resistivity survey were incorporated to develop HiRAS technique. CapSASW method is a good method for evaluating material stiffness and PDC-R technique is a reliable method for determination of underground stratification even in a site with electrical noise. For the inversion analysis of HiRAS techniuqe, a site-specific relationship between stress-wave velocity and resistivity was employed. As for outgrowth of this research, the 2-D distribution of Poisson's ratio could be also determined.

• Journal of Plant Biology
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• v.32 no.1
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• pp.23-32
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• 1989

We have developed a plasmid vector, pKCH1, for the purpose of higher plant transformation. It contains the promoter region of cauliflower mosaic virus 35S transcript (P35s) and the terminator region of nopaline synthase gene (Tnos) with unique cloning sites, Bam HI and Xba I, between them. After inserting a foreing gene at the cloning sites, P35s-foreign gene-Tnos cassette can be recovered by using a restriction enzyme Hind III.

• Microbiology and Biotechnology Letters
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• v.18 no.6
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• pp.647-652
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• 1990

The production of delta-endotoxin crystal and the cloning of endotoxin protein gene in Bscillus thuringiensis subsp. kurstaki HD1 strain were studied. The strain produced bipyramidal crystals ($2.9\times 1.0 \mu m$) in their cells during sporulation. The B. thuringiensis contained about 10 plasmid DNA elements ranging from 2.1 to 80 kilobases. The 73 kb plasmid DNA, the 29 kb BamHI fragment and the 7.9 kb Pstl DNA fragment hybridized to the pHL probe. The 7.9 kb fragment was eluted and cloned in the PstI site of pBR322 vector and transformed into E. coli HB101, which produced insecticidal proteins killing Bornbyx mori larvae.

• Journal of Plant Biology
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• v.37 no.3
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• pp.349-355
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• 1994

Viral RNA was extracted from a purified orchid strain of tobacco mosaic virus (TMV-O) from Cymbidium "Grace Kelly". Polyadenylated viral RNAs were primed with Not I-oligo (dT) primer-adapter. First-strand cDNAs were reversely transcribed by Moloney murine leukaemia virus reverse transcriptase (RNAse H-), and then second-strand cDNAs were synthesized by RNase H and DNA polymerase I. The resulting double-stranded cDNAs were ligated into pSPORT1 vector and transformed into competent E. coli strain JM109 cells. The size of cDNAs within the recombinant plasmids was ranging from 0.9 to 3.9 kb. Among the selected clones, pTMO-0205 and -0210 covered the 3' half and the 5' half of the viral genomic RNA, respectively, which were covering more than 99% of the viral genemo size based on sequencing analysis. Two cDNA fragments which were 3.1 kb BamHI and NotI fragement released from pTMO-0.205 and 3.3 kb SalI and BamHI fragment released from pTMO-0210 were ligated with T4 DNA ligase. The clone was almost entire length, lacking only 31 nucleotides from the 5' terminus based on the sequencing result. This method was shown to be efficiently applicable to other plant viral gnomic RNA for the construction of cDNA.n of cDNA.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.575-582
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• 1991

To increase the production of glutathione by the expression of recombinant gsh plasmids, two genes responsible for the biosynthesis of glutathione were isolated and cloned. To clone a gshI gene, the GS903 mutant strain, which is deficient in $\gamma$-glutamylcysteine synthetase activity, has been raised. A gshI gene was cloned using pBR322 plasmid as a 3.6 Kb PstI DNA fragment isolated from E. coli K-12 chromosomal DNA. Also a gshIl gene was cloned using pUC13 plasmid as a 2.2 Kb PstI-BamHI DNA fragment. To study the effects of plasmid copy number and passenger DNA size on the expression levels of the gsh genes, various recombinant plasmids containing different sets of genes were constructed. The expression levels of the gsh genes were increased approximately twice higher in pUC series plasmids than that in pBR322 plasmid. But the sizes of the passenger DNA containing the gsh genes in the vector plasmid did not affect on the expression levels of the gsh genes.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.259.1-259
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• 1998

No Abstract, See Full Text